The dynamic host configuration protocol (DHCP), described in RFC 2131, the disclosure of which is incorporated herein by reference, is used to automatically assign IP addresses and other parameters to network devices, such as computers, routers, gateways, servers, local branch boxes and other processing units connected to a network. The automatic assigning of IP addresses avoids the need of a skilled person to configure the network device with the address. The use of DHCP is described, for example, in U.S. Pat. No. 7,096,273 to Meier, the disclosure of which is incorporated herein by reference.
DHCP may be used to provide an arbitrary IP address which changes over time. It may, however, be desired that a device have an IP address that does not change over time.
U.S. Pat. No. 6,807,184 to Gutknecht et al., the disclosure of which is incorporated herein by reference, describes a DHCP server which keeps track of MAC addresses and/or PC hostnames of devices to which it assigns IP addresses and the IP addresses assigned to the devices. Further requests for IP addresses are assigned the same IP addresses.
U.S. Pat. No. 6,957,276 to Bahl, the disclosure of which is incorporated herein by reference, similarly describes methods for reclaiming a previously assigned IP address.
In some cases, however, it is desired that devices be configured with a static IP address pre-planned for the network device.
U.S. Pat. No. 6,775,273 to Kung et al., the disclosure of which is incorporated herein by reference, describes assignment of an IP address to a device based on the MAC address of the device.
U.S. Pat. No. 6,212,563 to Beser, the disclosure of which is incorporated herein by reference, describes use of DHCP with a preconfigured client ID, to assign a static IP address.
These two patents, however, require knowledge in advance of the MAC address or the client ID of the device. Such knowledge requires either configuring the device with a desired value, an act which requires a trained person in the site of the device or on its way to the site, or marking an attribute of the device for further use.
In addition to assigning IP addresses, DHCP is used to provide devices with operation parameters. The parameters may be configured into the DHCP server according to the hardware address of the device, the IP address of the device or any other unique identifier of the device. In addition, parameters, such as the addresses of peripherals and/or default values of QoS or other fields of packets they transmit, may be defined for groups of devices, such as all devices of a specific vendor and/or all devices in a specific network.
U.S. patent publication 2006/0133332 to Achanta, the disclosure of which is incorporated herein by reference, describes assigning parameters to mobile access points using DHCP.
U.S. patent publication 2004/0153550 to Payeur, the disclosure of which is incorporated herein by reference, describes a method of customization of DHCP option rules.